We are superseding an existing airworthiness directive (AD) for the products listed above. That AD currently requires removing certain propeller hubs from service at new, reduced life limits and eddy current inspections (ECIs) of the propeller hub. This new AD requires removing certain propeller hubs from service before they exceed 6,000 hours time-since-new (TSN). This AD was prompted by a report of a crack in a propeller hub. We are issuing this AD to prevent cracked propeller hubs, which could cause failure of the propeller hub, blade separation, and loss of control of the airplane.